An apparatus for transporting workpieces within a press installation, in particular for transporting vehicle body parts within a press installation for the automobile industry typically has at least one transfer bar extending along a longitudinal bar axis extending generally parallel to a horizontal Y axis, to which bar one or more tool assemblies, for example gripper arms, are attached or can be attached. The transfer bar is seated at its two ends in respective X slides that can move along a horizontal transfer or X axis, and the bar can also preferably be raised and lowered along a vertical Z axis.
This type of transfer apparatus is employed in practical applications in press installations or press lines such as, for example in the automobile industry. In this way, workpieces, for example vehicle body parts, can be transported for example within a press line from one press or press stage to the next press or press stage, or from one treatment apparatus to a downstream treatment apparatus. An essential component of a transfer apparatus is the transfer bar to which typically a plurality of tool assemblies, for example gripper arms, are attached that can be equipped with suction bars so that the transfer bar as a whole can also be identified as a suction bar and is equipped with appropriate negative-pressure vacuum connections. The transfer bar can typically be moved and/or rotated in various directions, thereby enabling the transfer to be flexible. Multiple gripper arms are preferably interconnected through common connecting tubes so as to create the tool assembly, which is also identified as a suction spider and can in its entirety comprise multiple suction cups.
DE 20 2012 104 324 discloses a transfer apparatus of the above-described type in which the transfer bar is provided so as to be longitudinally modifiable and is composed of a first bar section and a second bar section that can each be displaced relative to each other along the longitudinal bar axis, and the first bar section movably fits within a female end of the second bar section through by a male end. The known transfer apparatus has a compact structure and allows for very flexible transfer of the workpiece while simultaneously providing high stability. Using the fundamentally known approach, the transfer bar can be moved by headpieces or X slides along the transfer X axis, while provision is also made whereby the transfer bar can be raised and lowered along the vertical Z axis. The two headpieces can optionally be moved relative to each other and thus along the Y axis, with the result that the length of the transfer bar is changed and thus changes the positions where grippers are attached to the transfer bar. The two halves of the transfer apparatus can also be moved in different ways from each other since the longitudinally movable transfer bar enables variations in length to be compensated for. While these known measures have proven successful in practice, it is still possible to develop them further.
In addition, U.S. Pat. No. 7,624,614 describes a transfer apparatus in which a vertical slide is held such that it can be raised and lowered by spindles along vertical supports. This vertical slide carries longitudinal supports that extend along the transfer axis and are also held such that they can be raised and lowered and also rotated about a horizontal axis. A transfer bar is held on these horizontal supports so as to be movable and also rotatable.